Then what's the point in prayer???
I appreciate your question.
If a child asks for a loaf of bread, will you give him a rock? No, you give him something to eat.
If a child asks for the latest and greatest blood and gore video game that all his friends are playing, you don't necessarily comply.
The child will probably not understand (nor want to understand) why the video game was denied. Just as we sometimes will not understand (nor want to understand) why a request of God, even a seemingly benign one like healing, was denied.
Does this mean that the child should quit talking to his parent? Sometimes the denied child may feel unloved and hurt...because their own understanding of what is important has not fully matured.
God's ways are not our ways. The wellness of a human body in this world is temporary at best. These bodies will always have some corruption in them until we leave them. They are not part of the treasure of heaven.
Now if I see somebody laying on hands and healing the sick, then praise God, that is one of the signs Jesus told us would follow the saints. However, I'm afraid we may not assume that every request for healing will be granted in this life. I have seen both miraculous healing, and I have seen people who I'm convinced have as much faith as anyone pray for miraculous healing and not receive it. Should I tell them then that their faith is a sham and they should fear for their very souls?
But yes, a child should certainly still talk to his or her parents, even if a heart-felt request was denied them. Trust God, He knows better than we do.